Traffic law violators are known to be a major cause for traffic automotive accidents, which are a major cause of loss of life and property. It is estimated that over ten million people are involved in traffic accidents annually worldwide and that of this number, about three million people are severely injured and about four hundred thousand are killed. A report “The Economic Cost of Motor Vehicle Crashes 1994” by Lawrence J. Blincoe published by the United States National Highway Traffic Safety Administration estimates that motor vehicle crashes in the U.S. in 1994 caused about 5.2 million nonfatal injuries, 40,000 fatal injuries and generated a total economic cost of about $150 billion.
Various attempts have been made to improve traffic law enforcement. An example of a laser based system, is disclosed in U.S. Pat. No. 7,164,118 (hereinafter U.S. Pat. No. '118), by Anderson et al. U.S. Pat. No. '118 discloses a method of detecting presence of an object and the distance between the system and an object using a laser mounted on an industrial vehicle. The transmitter emits linear beams of electromagnetic radiation with a transmitted radiation pattern within a defined spatial zone. A camera collects an image of the defined spatial zone. A data processor detects a presence of an object in the collected image based on an observed illumination radiation pattern on an object formed by at least one of the linear beams. A distance estimator estimates a distance between the object and the optical device.
There are also prior art systems using imaging devices to image the scene in an angle 360° horizontally around a vehicle. Such a system is disclosed in U.S. patent application 2004/0075544 (hereinafter US '544), by Janssen Holger. US '544 uses two optical sensors that act as a pair of stereo cameras. The sensors are coupled with fisheye lenses, which have a very wide-angle of 220°. Thus, a large portion of the surroundings of the motor vehicle may be detected but the very wide-angle lenses provide images with a large extend of distortion, and US '544 does not disclose if the distortion is corrected. In US '544 all sensors emit the sensed information to a single controller. US '544 suffers from a tradeoff between covering large field of view and achieving detailed images of distant objects. Employing very high resolution cameras incurs a significantly high added expense. The same is true for other known 360° degree systems.
It would be desirable to provide an automated traffic violation monitoring system and method for tracking, identifying and recording traffic violations in a 360° field of view around the system. It would also be desirable to provide such a system and method that achieves detailed images of distant objects without the added bandwidth and expenses of very high resolution cameras. It would also be desirable to provide such a system and method that uses GPS location technology to provide comprehensive violation data as evidentiary records for traffic violation enforcement. It would also be desirable to provide a side-ways looking system to improve traffic violation detection and provide improved evidentiary records of traffic violations. Side looking cameras improve position estimation along the longitude axes which provides a more accurate assessment of the distance between vehicles. In addition, side looking cameras improve the ability and efficiency of tracking a vehicle moving between various fields of view, while maintaining a positive identification of the vehicle and an improved ability to assess a traffic violation such as passing on the wrong side.
Thus, there is a need for and it would be advantageous to have a system including multiple cameras mounted on a law enforcement vehicle or concealed therein, having side looking cameras, for automatically detecting and recording in real time traffic law violation events in a manner so as to provide evidentiary records for traffic violation enforcement purposes.
The term “Field Of View” (FOV) in general is the angular extent of a given scene, delineated by the angle of a three dimensional cone that is imaged onto an image sensor of a camera, the camera being the vertex of the three dimensional cone. The FOV of a camera is determined by the focal length of the lens: the longer the focal length, the narrower the field of view. The terms “Field Of View” of a camera and “viewing zone” of a camera are used herein interchangeably and are used herein to refer to the horizontal angular extent of a given scene, as imaged on to the image sensor of the camera. It is assumed that the dimensions of the detector are adapted to the camera FOV. The term “wide angle camera” in this documents refers to cameras with a FOV that is relatively wider then those of “narrow angle camera”
The term “an angle 360° around a vehicle” as used herein refers to the combined viewing zone as viewed by all wide FOV cameras. The combined viewing zone as viewed by all wide FOV cameras is not necessarily continuous, and there can be “blind” gaps between the viewing zones of two adjacent wide FOV cameras. FIG. 4 is an example of a top view of an embodiment of a traffic law violation detection and recording system 100 of the present invention, configured with a host vehicle 10 and four wide angle cameras. Viewing zones 52 viewed by the left and right looking cameras 50b and 50c are considerably wider than the front and back looking cameras 50a and 50d, and wherein each viewing zone 52 is separated from a neighboring viewing zone 52 by a diverging blind gap/zone 53. The four wide angle cameras are said to monitor “an angle 360° around the vehicle”.
The term “primary relative directions” is used within the scope of this application to refer to the relative directions of forwards, backwards, to the left and to the right.